Flexible bags, particularly those made of comparatively inexpensive polymeric materials, have been widely employed for the containment and/or preparation of various food items and/or materials.
As utilized herein, the term "flexible" is utilized to refer to materials which are capable of being flexed or bent, especially repeatedly, such that they are pliant and yieldable in response to externally applied forces. Accordingly, "flexible" is substantially opposite in meaning to the terms inflexible, rigid, or unyielding. Materials and structures which are flexible, therefore, may be altered in shape and structure to accommodate external forces and to conform to the shape of objects brought into contact with them without losing their integrity. Flexible bags of the type commonly available are typically formed from materials having consistent physical properties throughout the bag structure, such as stretch, tensile, and/or elongation properties.
With such flexible bags, it is frequently difficult to provide adequate protection from crushing or impact damage to fragile food items such as potato chips. Moreover, the generally planar nature of most films, coupled with their thermal conductivity, typically results in a high degree of surface contact between the protected food item and the film and a corresponding high degree of heat loss or heat gain for the protected item. Most such films also are impermeable to air and moisture transfer, such that excess humidity can build up within the bag when items such as produce are placed therein.
Accordingly, it would be desirable to provide a flexible bag which is capable of providing increased protection of food products therein under in-use conditions.